The specific purpose is to continue the progress already made in the history of the development of the knowledge of neurophysiology. The study of this in the 17th and 18th centuries, which culminated in Galvani's discovery of bioelectricity, has been completed and published. At this time, the work on the 19th century has reached 300 typewritten pages and 90 figures. This application is for support to complete the 19th century and follow the work of the investigations into the 20th century. In the case of the 19th century study. Still to be researched are the following subsections: a) The discovery of the electrical activity of the brain; b) The development of the Russian school of neurophysiology. This entails translation from both German and Russian sources for material not yet available in the English language; c) The opening of the careers of Sherrington and Pavlov - material to be expanded in the later volume on the 20th century research. Pavlov's contributions have been exhaustively studied from the viewpoint of the behavioral sciences but neurophysiology of his school is scarcely represented in the English language. The first half of the 20th century sees the development of studies in axonology as developing in the St. Louis school, the College de France, the Cambridge school, the Rockefeller Foundation and the Harvard Medical School. This will cover the discoveries of the all-or-none law, (Gotch 1902), of the compound action potential 1924, the refractory period 1925 (Gasser and Erlanger). The progress engendered by the Braun tube will be detailed. This will be followed by the history of the analysis of the electrical fields around neurons, activity at first analyzed in 2 dimensions laying the foundation for (thanks to computers) analysis in 3 dimensions. The impact of this new knowledge of the brain's electrophysiology (not yet to be found in the textbooks) will be developed and its history documented, (4) In the 20th century the fundamental 19th century research on the electrical stimulation of the brain was brought to use in neurosurgical work with human patients. With the cut-off point for the 20th century being 1950, this will enable presentation of the history of the early development of computers and their first applications to study of the nervous system.